Fix race condition in AwesomePlayer

This fixes a race condition that could cause two threads to attempt to
connect to a server at the same time, resulting in multiple requests
and/or aborted connections. In some cases, it could cause other operations
on MediaPlayer to block until network access was complete.

b/13187722

Change-Id: Ibf78acff15dbfbf6c443a4c60623e8eac967d955
diff --git a/media/libstagefright/AwesomePlayer.cpp b/media/libstagefright/AwesomePlayer.cpp
index e83ec62..4bad14b 100644
--- a/media/libstagefright/AwesomePlayer.cpp
+++ b/media/libstagefright/AwesomePlayer.cpp
@@ -2217,6 +2217,10 @@
 
         mLock.unlock();
         status_t err = mConnectingDataSource->connect(mUri, &mUriHeaders);
+        // force connection at this point, to avoid a race condition between getMIMEType and the
+        // caching datasource constructed below, which could result in multiple requests to the
+        // server, and/or failed connections.
+        String8 contentType = mConnectingDataSource->getMIMEType();
         mLock.lock();
 
         if (err != OK) {
@@ -2247,8 +2251,6 @@
 
         mConnectingDataSource.clear();
 
-        String8 contentType = dataSource->getMIMEType();
-
         if (strncasecmp(contentType.string(), "audio/", 6)) {
             // We're not doing this for streams that appear to be audio-only
             // streams to ensure that even low bandwidth streams start